An important step. The United States Food and Medicines Administration (FDA) gave its green blood test to the first blood test for Alzheimer’s diagnostic disease, a promising technology that could soon reach Europe and France.
Alzheimer’s disease is the most common way of dementia. Go over time, gradually depriving people with their memories and independence. 17% of people over 75 are affected, according to Alzheimer’s defeat Foundation. But if the disease affects hundreds of thousands of patients, only 1 in 2 is properly diagnosed.
How does this test work?
The test, developed by the Japanese firm Fujirebio Diagnostics, measures the presence in the blood of beta amyloid protein and the Tau protein, the characteristics of Alzheimer’s disease. Due to their very small amount, so far they were not detectable during a blood test.
Keep in mind that a positive test does not automatically mean that the person suffers the disease. “In fact, it is a diagnostic test and not an evaluation,” said Professor Philippe Amouyel, general director of the Alzheimer’s Foundation, at BFMTV.com.
When detection detects the presence of an early stage disease in healthy people a priori, the Fujirebio diagnostic test is aimed at patients who already have symptoms and should be confirmed by other clinical information, such as neurocognitive tests.
“The proteins we are looking for are in large quantities in patients with Alzheimer’s, but are also found in small amounts in people who do not have Alzheimer’s disease. The test is so sensitive that the disease could be detected erroneously,” continues the specialist.
What is the advantage of blood analysis?
Today, the diagnosis of Alzheimer’s disease can be done from different exams: neuropsychological tests, magnetic resonance, positron emission tomography (or PET exploration, images that measure metabolic activity). Doctors can also carry out a lumbar puncture that will measure the proteins found in large quantities in a patient’s brain with Alzheimer’s disease.
“With these elements, and when observing the evolution of the symptoms, a diagnosis of dementia syndrome is made. Because Alzheimer’s is 70 to 70% of the forms of dementia, but there are other forms such as Lévy’s body disease or frontal-temporal dementias,” explains Professor Philippe Amouyel.
The problem of these exams is that they are “relatively heavy, that they take time and, for the lumbar puncture, they are still quite invasive.” The simplest and faster blood analysis is, therefore, a real advance.
Towards better patient care?
There are currently two approved treatments of Alzheimer’s, Lecanemab and Donanemab, which are directed to the amyloid plate and modestly slow down the cognitive decline, without allowing total healing.
Another treatment that acts in the first phase of the disease, Leqembi, has just been authorized by European authorities, but is not yet accessible in France.
The supporters of these treatments, including many neurologists, argue that they should be taken before to be effective.
“The better we treat the disease early, the better the intellectual functions are. Because what characterizes progress in the disease is the loss of neurons and neurons do not grow again,” said Professor Philippe Amouyel.
“The objective is to give these treatments to patients who have sufficient cognitive reserve to continue living normally without a matter of dependence. Therefore, it must do a test quite quickly, which blood analysis allows,” he concludes.
Who is the test for?
The test is authorized in the clinical environment for patients who are already signs of cognitive impairment.
“These are patients whose disorders, memory, but not only, lead to social discomfort for them or their loved ones,” recalls Professor Philippe Amouyel.
In France, the general practitioner directs patients who think of being affected by Alzheimer’s “memory centers” that make more advanced diagnoses. “It is in this context that, at first, the test must be developed,” says Philippe Amouyel.
When will you get to France?
A marketing application has been submitted to the European authorities, and an answer is expected in the fall. Therefore, it could be available in France next year.
The authorization process is faster for a test than for a drug, says Philippe Amouyel. “We do not judge the balance of benefit risk but sensitivity, the ability to give the correct answer. Therefore, it should go fast.”
Source: BFM TV
